Expansible pulley.



Patented Apr. -l0, I900 B. TEMPLE.

EXPANSIBLE PULLEY.

(Application filed Dec. 19, 1899.)

2 Sheets-Sheet I,

(No Model.)

142/ mum,

NITED STATES PATENT OFFICE.

ROBERT TEMPLE, OF DENVER, COLORADO, ASSIGNOR TO THE TEMPLE GAS ENGINEAND MACHINE COMPANY, OF SAME PLACE.

EXPANSIBLE PU LLEY.

SPECIFICATION forming part of Letters Patent No. 647,429, dated April10, 1900. Application filed December 19, 1899. Serial No. 740,906. (Nomodel.)

To all whom it may concerns I Be it known that I, ROBERT TEMPLE, acitizen of the United States, residing at Denver, in the county ofArapahoe and State of 0010 rado, have invented a certain new and usefulImprovement in Expansible Pulleys,of which the following is a full,clear, and exact description.

This invention relates to that class of apparatus by which a change ofspeed of a shaft or other object may be instantly obtained by means of adriving-pulley the diameter of which may be changed. Such pulleys arecommonly known as expansible pulleys.

In carrying out my invention I provide a cone of rods, as I shallhereinafter designate it,which',is movable longitudinally within aband-pulley, the latter being fixed relatively to the driven shaft andhaving a peripheral surface which may be expanded and contracted by thelongitudinal movement of the cone of rods, so as to increase anddecrease, respectively, the diameter of the pulley, and thuscorrespondingly affect the speed of the belt or band. Such an apparatusmay be used to transmit motion to an ordinary band-pulley, or it may beused with a second expansible pulley, and in the latter case the twopulleys will be connected for simultaneous operation in such manner thatas one pulley is expanded the other pulley will be contracted; andanother feature of the invention is the provision of means for taking upslack in the belt or band.

Having thus stated the principle of my invention, I will proceed todescribe the best mode in which I have contemplated applying thatprinciple and then will particularly point out and distinctly claim thepart, improvement, or combination which I claim as my invention.

In the accompanying drawings, illustrating my invention, in the severalfigures of which like parts are similarly designated, Figure l is a planView illustrating one form of my invention with the pulley at or nearits most c0ntracted or smallest state. Fig. 2 is a longitudinal section,on a larger scale, of the expansible pulley in the position andcondition shown in Fig. 1. Fig. 3 is a plan view illustrating one formof a pair of expansible pul- I leys. Fig; 4 is an elevation of one ofthe pair of complemental disks which form the sides of the band-pulley.tions of the two disks forming the opposite ends or sides of the cone ofrods, so called. Fig. 7 is a perspective view of one of the sectors orblocks forming the belt-receiving surface of the band-pulley. Fig. 8 isa longitudinal section of an expansible pulley to be used in pairs withone form of means for taking up the slack in the belt or band.

I have shown merely conventional accessories for mounting my expansiblepulley, and, referring to Fig. 1, a may represent ,a frame, in which issuitably mounted a shaft 1), which maybe driven by a pulley c or anyother mechanism. This shaft has mounted upon it loosely a disk 01 of onediameter and another disk 6 of larger diameter, and these disks areunited by a series of rods f, some or all of which may be screw threadedinto the disk cl and secured to the disk 6 by nuts g, as shown moreparticularly in Fig. 2, in such manner that the said disks and rods forma cone of rods, as hereinbefore and hereinafter referred to, the realformation being that of a skeleton truncated cone.

The diskehas ahub h,upon which is mounted a ring t, having trunnion-likeopposite projections j, and this ring is held in place by means of acollar 7t,secured to the hub 7t by a set-screw Z, and arranged to permitthe cone of rods to revolve without carrying around with it the saidring '6. The projectionsj of the ring c' are engaged by a fork m on alever n, and this lever is provided with any suitable latch and toothedrack to hold the cone of rods in any adjusted position longitudinally ofthe shaft given to it by means of the movement of the lever it. Ofcourse I do not limit my invention to the means described for shiftingthe cone of rods longitudinally and simply show the device described asone means for accomplishing that purpose.

' The pulley itself or that portion of the device which receives theband or belt is composed of similar or complemental disks 0, which aremade fast to the shaft 1), so as to rotate therewith, by any suitablemeans, such as the keys 19. These disks are slotted radially, as shownmore especially in Figs. 2 and 4;

Figs. 5 and 6 are eleva at q, and in these radial slots are arranged theperipheral blocks through which the rods f of the cone of rods passobliquely, the said rods also passing through the radial slots in thedisks 0. The blocks 1" are provided with end lugs 1", which are adaptedto enter the slots (1 in the disks 0 to hold the'said blocks between thesaid disks and guide them in their inward and outward movements, theends of the blocks, adjacent to said disks working against the adjacentfaces of the said disks. The blocks 0* constitute the surface upon whichthe belt or band is supported.

The various blocks which constitute the belt-receiving surface of thepulley are made as sectors of a cylinder, and their belt-receivingsurfaces may be flat or crowning or curved or otherwise prepared orformed to receive the character of belt orband which is to be used;butin any case the belt-receiving surfaces formed by these blocks isessentially a cylinder, and by using a'great number of small blocks andacorresponding number of rods the continuity of the belt-receivingsurface from the smallest to the largest diameter -may be more perfectlypreservedthan if a few blocks were used, and thus a'very perfect and:

' complete contact with the belt is possible in pulley is supported atboth ends by'the lugs,

all the variations of the diameter of the pulley.

It will be observed that each of the blocks constitutin g thebelt-receiving surface of the which slide in the-radial slots of thedisks 0, and bycontact with said disks, and the result of thisconstruction is that the pull of the belt is transmitted directly to thedisks with w the rods constituting the cone of rods are largely relievedof strain. It will be observed 4 verylittle strain on the cone of rods,and'thus also, inasmuch as the band-pulley itself, con- -:sisting of thedisks 0 and blocks 0, is fixed to'the shaft 1) and turns with it and thecone I will contract or expand the diameter of theof rods is capable ofa longitudinal motion through said band-pulley, that the movement ofsaid cone of rods to the right or to the left V band-pulley by movingthese blocks toward the center or toward the circumference, re-

specti-vely, and thus the transmitted speed will be varied as may bedesired, and this "change of speed may be effected without stopping themachinery.

- Whenthese pulleys'are used in pairs and operate simultaneously, a beltpassing over the pulleys, if taut when the pulleys are of extremedimensions, (one large and one small,)

- would be slackened somewhat when the pulleys are of intermediatediameters, thus tendingto make the belt slip.

8, which makes the pulleys in their intermediate positions a littlelargerin diameter than would be the case if the rods were straight,

thus regulating the change in the diameters of the pulleys, so as torequire a constant "length of belt and make the belt equally taut in allpositions of the pulleys. This would not be so if'the rods werestraight. In Fig. 8 the arc of curvature is exaggerated in order todirect attention to the fact of curvature; but in practice thiscurvature is but very slight.

' In Fig. 3 I have shown one arrangement in which two expansible pulleysare to be banded together, so as to transmit motion from a driving to adriven shaft. The letter 8 may designate the driving-shaft, having anexpansible pulley of the character just described, and i may be thedriven shaft, also having a similar expansible pulley, but arrangedreversely tothe pulley on the shaft 8. The mechanism for operatingsimultaneously the two cones of rods may comprise a rigid angularconnecting-rod it, connected with the hubs of the cones of rods andsupported upon a vibrating guide o, suitably suspended from any fixeddevice or frame, the said guide having pivoted to it an operating-leverw, which and thus tends to force and hold the two cones of rods towardthepulleys, so as to exert atightening action upon the belt, and therebykeep the belt taut. Of course this automatic action of the springy onthe coneconnecting rod is entirely independent of the action of theshifting lever w.

The curving of the rods shown in Fig.8 obviates-the necessity of thespring y and also thenecessity of pivoting the rod 1;, which latter canbe fastened rigidly at each end in such case.

The rods of the cone of rods may be of circular,square, oblong, or othershape in crosssection, as may be desired.

complemental disksnfixed to said shaft and provided with radial slots, aseries ofblocks ofthe form of'sectors of a cylinder and provided at eachend with lugs arranged in said slots, another pair of disks freelymounted upon saidshaft and of different diameter, and a series ofinclined rods connecting the Iastunentioned pair of disks and forming acone of rods which as a whole is adapted to be slid longitudinally ofthe shaft,'each of said rods passing obliquely through a block and theadjacent slots in the first-mentioned disks, whereby, when the cone ofrods is moved longitudinally of the shaft the said blocks will be movedradially outward or intially a cone of rods, a shaft upon which it isloosely mounted, means to move said cone of rods longitudinally of theshaft, a pair of disks fixed to said shaft and slotted radially, therods of the cone of rods passing through said slots, and a series ofblocks through which said rods pass obliquely and havingend lugsengaging said radial slots in said fixed disks,vwhereby as the said coneof rods is moved longitudinally of the shaft the eX- pansion andcontraction of the pulley is effected, substantially as described.

3. The combination of a shaft, two parallel complemental disks fixed tosaid shaft and provided with radial slots, a series of blocks, eachblock being of the form of a sector of a cylinder and provided at itsopposite ends with lugs arranged in opposite parallel radial slots andthereby adapting the blocks to slide in said radial slots, and a coneofrods arranged upon said shaft and adapted to be slid longitudinallythereon, each of the several rods of the cone of rods passing throughadjacent slots in the complemental disks and through the block therein,whereby when the said cone of rods is moved longitudinally of the shaft,the said blocks will be moved radially outward or inward respectively toincrease or diminish the diameter of the pulley formed by the said disksand their blocks, substantially as described.

4. An expansible pulley,comprisinga shaft, a pair of disks fixed to saidshaft and slotted radially, sliding blocks arrangedin said slots at andbetween the said disks, and acone of rods mounted loosely upon the saidshaft and capable of longitudinal motion thereon, the rods of the saidcone of rods having an outward curvature and passing obliquely throughthe blocks, substantially as described. I

In testimony whereof I have hereunto set my hand this 16th day ofDecember, A. D.

ROBERT TEMPLE. Witnesses:

FREDERICK O. VAILLE, JOSEPH S. DAVIS.

